title: Diffusion-weighted magnetic resonance imaging of the pancreas: diagnostic benefit from an intravoxel incoherent motion model-based 3 b-value analysis.
abstract: OBJECTIVE
  The objective of this study was to evaluate the diagnostic benefit of an intravoxel incoherent motion (IVIM) model-based characterization of pancreatic masses from diffusion-weighted imaging (DWI) with 3 b values.
  
  
  METHODS
  This retrospective study had an approval from the institutional review board, and informed patient consent was waived. The 1.5-T DWI data of 42 patients with or without pancreatic disease, acquired by a respiratory-gated spin-echo echo-planar imaging sequence with 3 b values (0, 50, 800 s/mm²), were retrospectively analyzed. The IVIM-related parameters D', which is the apparent diffusion coefficient [ADC(50,800)], and f', as well as ADC(0,50), and conventional ADC(0,800) were calculated voxelwise. Regions of interest were analyzed in pancreatic adenocarcinomas (CAs, n = 12), neuroendocrine pancreatic tumors (NETs, n = 9), and chronic pancreatitis (CPs, n = 11), not affected tissue of each pathologic group, and in the head, body, and tail of the healthy pancreas (n = 10).
  
  
  RESULTS
  By ADC(0,800) and D', CAs could hardly be distinguished from neuroendocrine pancreatic tumors and chronic pancreatitis. However, CAs revealed very low ADC(0,50) and f' values, which differed significantly from all other groups. In the healthy pancreas, ADC(0,800) and D' values were significantly higher for the head than for the body and tail, but no significant differences were found for ADC(0,50) and f'.
  
  
  CONCLUSIONS
  The determination of IVIM-based microcirculation-sensitive parameter maps from DWI with 3 b values significantly improved the discrimination of CAs from NETs, CPs, and the healthy tissue.
authors.affiliation: From the *Department of Radiology, University of Bonn, Bonn; †Institute of Medical Engineering, Ruhr-University Bochum, Bochum; ‡Department of Internal Medicine 3, University of Bonn, Bonn, Germany; and §Philips Healthcare, Best, The Netherlands.
authors.forename: Massimo
authors.initials: M
authors.lastname: Concia
authors.forename: Alois M
authors.initials: AM
authors.lastname: Sprinkart
authors.forename: Arndt-Hendrik
authors.initials: AH
authors.lastname: Penner
authors.forename: Peter
authors.initials: P
authors.lastname: Brossart
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gieseke
authors.forename: Hans H
authors.initials: HH
authors.lastname: Schild
authors.forename: Winfried A
authors.initials: WA
authors.lastname: Willinek
authors.forename: Petra
authors.initials: P
authors.lastname: Mürtz
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D002908:Chronic Disease; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009038:Motion; D009068:Movement; D018358:Neuroendocrine Tumors / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000473:pathology*; D010195:Pancreatitis / Q000473:pathology*; D015203:Reproducibility of Results; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity